Five-year pneumo booster encouraged for elderly

Vaccine use can prevent nursing home outbreaks

The Centers for Disease Control and Prevention is re-emphasizing the importance — and safety — of both primary vaccination and revaccination with pneumococcal vaccine for the elderly and other high-risk patients. In particular, a recent study showed that re-immunization posed only low risk of short-term side effects.¹

Most people need to be immunized only once with pneumococcal polysaccharide vaccine, but the elderly and others of all ages with poor immune function need a second shot after five years. In particular, those 65 or older should receive a second vaccine dose if they were previously immunized more than five years ago and if they were younger than 65 at that time, the CDC recommends. People with compromised immune systems should be revaccinated five or more years after their first vaccinations, which can be administered at any time of the year.

The study compared rates of injection site reactions, such as redness or swelling, in two groups of older adults. One group received the vaccine for the first time; the other group received a second vaccine five years or more after the first injections. The study found that 3% of first-time vaccinees reported a reaction and 11% of revaccinees reported a reaction.

No serious or unexpected side effects from the vaccine were observed during the study. Specifically, revaccination was associated with an approximate three-fold higher risk of a local reaction in the form of redness and swelling. The reactions were self-limiting and resolved a median of three days after revaccination.

40,000 deaths per year

Annually in the United States, Streptococcus pneumoniae accounts for an estimated 3,000 cases of meningitis, 50,000 cases of bacteremia, 500,000 cases of pneumonia, and 7 million cases of otitis media. Fatalities are highest among those with bacteremia and meningitis. Among the elderly with pneumococcal bacteremia, the mortality rate is 30% to 40%. Pneumococcal disease is the leading cause of vaccine-preventable deaths. Each year, it causes the deaths of approximately 40,000 Americans, most of them over 65 years of age.

CDC data suggest that nearly half of those deaths could be prevented if people 65 and older and others in high-risk groups were given pneumococcal vaccine. However, the CDC estimates that only about 45% of people 65 and older have been immunized against pneumococcal disease, which is far short of the goal of 60% (80% in nursing homes).

The vaccine study was conducted in 1996 and 1997 by the CDC and researchers from the Immunization Studies Program of the Center for Health Studies/Group Health Cooperative of Puget Sound in Seattle. More than 1,400 Group Health Cooperative members who were 50-74 years of age were recruited for the study. The CDC says misconceptions about adverse reactions contribute to low pneumococcal immunization rates, which have been cited in nursing home outbreaks as contributing to increased morbidity and mortality among residents.² (See Hospital Infection Control supplement, Healthcare Infection Prevention, December 1997, pp. 1-3.)

"Health care providers should inform patients that although there is a higher risk for adverse reactions with revaccination, the potential benefits of revaccination outweigh this overall low risk," says study investigator Lisa Jackson, MD, of the Center for Health Studies. "This study should reassure providers that the concerns of more serious side effects from revaccination are not substantiated."

Moreover, strains of drug-resistant S. pneumoniae have become increasingly common in the United States and in other parts of the world, further emphasizing the need for preventing pneumococcal disease by vaccination. The current pneumococcal vaccine contains the six strains of Streptococcus pneumoniae that are most frequently associated with drug resistance in the United States. Pneumococcal diseases together with influenza and other vaccine-preventable diseases now cost an estimated $10 billion each year. Approximately 90% of all costs associated with treating pneumococcal infections are for required hospital care.

"Pneumococcal vaccine has been shown to be a safe and effective way to prevent death and disease in vulnerable populations, yet it remains underutilized," says Scott Dowell, MD, CDC medical epidemiologist. "We hope that this study will help lower one barrier to immunization — fear of adverse pneumococcal vaccine, including the revaccination when needed."

The CDC recommends that the pneumococcal vaccine be administered to people:

• aged 65 or older;

• aged 2-64 who have chronic illness such as chronic cardiovascular disease, chronic pulmonary disease (but not asthma), diabetes, alcoholism, chronic liver disease, or cerebrospinal fluid leaks;

• aged 2-64 who lack a functioning spleen (those with sickle cell disease or splenectomy);

• aged 2-64 who are living in special environments in which there is a higher risk for severe pneumococcal disease (Alaskan natives, certain American Indian populations, residents of nursing homes and long-term care facilities);

• aged 2 or older with compromised immune systems including those with HIV infection.

• Those aged 65 or older should receive a second vaccine dose if they were previously immunized more than five years ago and if they were younger than 65 at that time.

References

1. Jackson LA, Benson P, Sneller VP, et al. Safety of revaccination with pneumococcal polysaccharide vaccine. JAMA 1999; 281:243-248.

2. Centers for Disease Control and Prevention. Outbreaks of pneumococcal pneumonia among unvaccinated residents in chronic-care facilities — Massachusetts, October 1995; Oklahoma, February 1996; and Maryland, Jan-June 1996. MMWR 1997; 46(No. 3).